Automatic weighing and indicating mechanism



Dec. 22, 1942.l w. TiMsoN. 2,306,197

AUTOMATIC WEIGHING AND INDICATING MECHANISM Filed Jan. 25, 1940l 2 sheets-sheet 1 De@ 22, 1942. w. nn/SON 2,305,197

AUTOMATIC WEIGHING AND INDICATING MECHANISM Filed Jn. 25, 1940 2 SheetS-Shee't 2 ,my e.

Patented Dec. 22, 1942 Ultli'lfbl STATES imtvihbli FilCE AUTGMATEC WEGHING AND KNDECATING MECHANISM William TimSon, Birmingham, England, assignor to W. e 'li. avery Limited, Birmingham, England l. Claim. l (Cll. 265--62) a rotatable indicating unit mounted in another ball bearing support, the said ball bearing mountings being vertically disposed in relation one to the other, and a plurality of ilexible metallic ribbons constituting the connection between the said units whereby a rotation of the one unit is positively communicated to the other unit.

A convenient embodiment of the invention will now be described with particular reference to the accompanying sheet of drawings, wherein:

Figure 1 is a iront elevation partly in section of the improved automatic weighing and indicating mechanism as embodied in a weighing scale of known kind and sufficient only of which is shown as is necessary to an understanding of the invention.

Figure 2 is a part sectional end elevation of the automatic weighing and indicating mechanism and of the portion oi the weighing scale illustrated in Figure l, and

Figure 3 is a fragmentary View in perspective showing in greater detail the arrangement of the flexible metallic ribbons for imparting rotation to the indicating mechanism.

According to the embodiment of invention c illustrated the pull ci the load is transmitted to the lower end oi a flexible metallic ribbon 5 the upper portion of which passes over the curved surface of a cam sector t and is clamped adjacent its upper end to the cam sector 5 by a. clamping plate 'l associated with the said cam sector. The cam sector t is mounted on an extension of the hub Se of a resistant sector 3 and is locked thereon by means of a set screw Ei, a pair of oppositely arranged set pins Sie being utilised for permitting oi the adjustment oi the cam sector 6 relatively to the resistant sector d, The hub da of the resistant sector t is xed by means of a set pin 9b on a spindle it which is rotatably mounted in ball bearing mountings i I which are I',

secured within the side walls of a frame I3. A mass I4 incorporating a vertically displaceable counterbalancing mass Ida is secured to one end of the resistant sector 8 said masses iii and I 4a in conjunction with the resistant sector 8 constituting the pendulous resistant unit.

At one end hereafter termed the upper end, the resistant sector ll carries a laterally projecting screw peg l5 which is locked in a set position by a screw pin I6 said peg I5 having anchored thereto one end of a flexible ribbon I'Ia the intermediate portion of which is rst drawn obliquely over the curved undersurface of the resistant sector 3 and then wound spirally around the periphery of a drum I8 the free end of the ribbon being anchored within a slotted portion i8@ of the drum i8. The other end of the cam sector 8 hereafter termed the lower end has clamped thereto one end of a complementary flexible ribbon I'lb which also is iirst drawn obliquely over the curved undersurface of the resistant sector 8 and then wound spirally but in an opposite direction around the periphery of the drum I3 said ribbon Hb being anchored in a slotted portion Ida of the drum I8 in a manner similar to the complementary iiexible ribbon I'l.

The drum I8 is secured to a spindle I9 henceforth termed the indicating spindle I9 which is mounted in ball bearing mountings 2t which are similar to the ball bearing mountings iI and which are located vertically below the said ball bearing mountings II. The indicating spindle i 9 has projecting ends on which 4are fixed graduated charts li which in conjunction with relatively iixed indices not shown permit of the observation of the weight from each side of the scale housing 22 within which the mechanism described is contained said drum I8, spindle i9 and charts 2l constituting the rotatable indicating unit.

The flexible metallic ribbon lla is associated with a clamping plate 23 and the flexible metallic ribbon i'ib with a clamping plate 24, the

- clamping plate 23 incorporating an extension 23a which serves to limit the swing of the resistant sector 3 in one direction while the clamping plate 24 incorporates an extension 24a which limits the swing of the resistant sector 8 in the opposite direction.

Since the complementary metallic ribbons Ila, lib are wound around the drum lil in opposite directions upon a pull being imparted to the ribbon 5 the cam sector and the resistant sector i3 are rocked and caused to impart a correspending rotation to the drum i6 and conscquently also to the graduated charts 2i.

The hub of the resistant sector 8 is provided with a boss 8b having therein a tapped hole 8C which can be engaged with the shank of a screw bolt 25 displaceably mounted in the upper end of the frame i3. Normally the screw 25 is maintained out of engagement with the hole 8c by a spring 25 but when it is desired to lock the unit the said screw 25 is pressed downwardly, with the indicating mechanism in the zero position, and the shank of the said screw engaged in the hole 8 in the boss thus looking the sectors 6 and S to the frame I3.

The peg i5 permits of the adjustment of the tension of the exible ribbon. Vla much in tho manner of a violin tuning peg.

1t will be appreciated that the whole of this weight resistant unit and rotatable indicating unit is mounted in a common framework, and

that the usual rack and pinion or like means for transmitting the motion from the resistant unit to the indicating unit is avoided, and that the use of any knife-edge or cone bearing support is also avoided.

The method of spirally winding and connecting the oppositely Wound exible metallic ribbons to the rotatable drum indicating unit admits of a complete rotation of the indicator over 360 or more should such a large degree `of rotation of the indicator be found to be desirable.

What I claim is:

Automatic weighing mechanism comprising, in combination, a frame carrying two sets of ball bearings, a sector pivoted in one of said sets of ball bearings, which is movable in response to the Weight of the load, a screw in said frame, extending toward said sector in an approximately radial direction and registering at one position of said sector with a tapped hole therein a spring for holding said screw normally out of engagement with said sector, an indicator shaft journaled in said other set of ball bearings, a drum on said shaft, ribbons having a portion fixed to said drum, which are wound in a spiral groove on said drum and extend obliquely along the arcuate face of said sector in opposite directions from said drum, and means for securing the remote ends of said ribbons to said sector.

WILLIAM TIMSON. 

